fix: update uri to omit deployment ids for assistant and thread paths

[CarterBland]

Summary:
Solves Assistants Support for Azure's new API version 2024-02-15-preview #430

Tested in my own local application and the URI with the deployment id omitted unblocks the whole process from creating an assistant, thread, and message.

Solution:
Support assistants API by removing the deployment id for certain paths

Example:
https://custom-domain.openai.azure.com/openai/deployments/gpt-35-turbo/assistants
to
https://custom-domain.openai.azure.com/openai/assistants

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[CarterBland]

@alexrudall Any status on this?

[alexrudall]

@alexrudall Any status on this?

Thanks for patience, I need to get access to Azure OpenAI so I can test this & other Azure PRs - hope to within next week or 2